he was thoughtful, no sense of bitterness and clinton told mandela on that trip that he was glad his heart did not return to stone. i returned to that cell just last year on a tour and there's been fresh paint, it's a national museum. but what strikes you is that the tour guides are former inmates. they all neuman dellaen an they talked to me what it was like to be with him in those tiny cells for so many years hoping one day that their corrupt would change. i sat down with his former son-in-law who also told me about what mandela meant to the country and to the family. >> we call him da da you know, we always respect that he's the foundation of this nation. he gave us, you know, these principles of humanity. as a foundation for the whole nation, he was able to coko cou down -- calm down the fire when south africa was about to explode. but he spoke a lot of sense to a lot of people who were angry about what had happened. ♪ happy birthday to you >> he's a father of the whole nation, not only in south africa, but all over the world. he's that symbol, reconciliation. you know. he taug